1. Field of the Invention
The present invention relates to a slider-position detector for detecting the position of the slider of a disk player.
2. Description of the Prior Art
In a disk player for playing an information recording disk (hereinafter referred to simply as "disk") such as a video disk, a digital audio disk, etc., a slider carrying a pickup is linearly moved in the radial direction of a disk. The slider is driven by a rotary motor through a mechanical transmission. A rack-and-pinion mechanism, for example, reduces the speed of the rotary motion of the rotary motor and converts the rotary motion into a linear motion to drive the slider for a linear motion.
The speed of the searching operation of the slider with the pickup, namely, an operation for searching a disk for a desired recording track while moving the slider at a high speed, is restricted since the response speeds of the mechanical transmission and the rotary motor are limited. Nevertheless, increase in the speed of the searching operation has been strongly desired in the industry. The speed of the searching operation of the slider may be increased by using a linear motor which has excellent response characteristics, instead of a rotary motor, as a driving source for driving the slider for a linear motion.
The friction coefficient between the slider using the linear motor and the guide rail is smaller than that using the conventional combination of the rotary motor and the rack-and-pinion mechanism, although the disk player is usually put on a stationary place. In the disk player employing the slider driven by the linear motor, the slider is liable to be accidentally moved due to external vibrations, in the stop mode. Therefore, the slider is shifted from a position to be stopped in the stop mode when the external vibrations acts on the disk player. In this case, the next movement of the slider is not smoothly executed.